Carbureter



E. F. McCART HY.

CARBURETEB.

APPLICATION FILED SEPT. 18, 1918- Patented June 1 4, 1921 E. F.McCARTHY.

CARBURETER.

APPLICATION FILED SEPT-18,1918.

Patented June 14, 1921,

3 SHEETS-SHEET 2.

2Q. i if V mardflflZ- WZ y E. F. MCCARTHY.

CARBURETEB.

APPLICATION FILED SEPT. 18, 1918.

Patented June 14, 1921.

3 SHEETSSHEET 3.

I M M UNHTED STATES EDWARD F. MCCARTHY, OF CHICAGO, ILLINOIS.

CARBURETER Specification of Letters Patent.

Patented June 14, 1921.

Application filed September 18, 1918. Serial No. 252,559.

T (117 1071-0122. 2'2 may con cern Be it known that I, Enwann F. Mc-AnrHr. a citizen of the United States. residing at Chicago, in thecounty of Cook and State of Illinois. have invented certain new anduseful Improvements in Carbureters, of which the following is aspecification.

This invention relates to improvements in carburetors. and one of theobjects of the invention is to provide a scientific. foolproof andeconomical apparatus of this character which will not only atomize theliquid fuel to its finest particles, but every globulc of fuel will besurrounded by its correct proportion of air, thereby insuring economy infuel consumption.

A further object of the invention is to provide a plurality ofregulating devices, all operating upon a single needle valve, each ofthe regulating devices being operable independently of the other and atthe will of the operator.

A further object is to provide an improved carhureter of this characterhaving an operating piston and compensating mechanism therefor. soarranged as to produce a compact structure and at the same time beinghoused to protect them from dust and dirt and also prevent them frombeing tampered with by inexperienced operators.

To the attainment of these ends and the accomplishment of other new anduseful objects as will appear, the invention consists in the features ofnovelty in substantially the construction. combination and arrange mentof the several parts. hereinafter more fully described and claimed andshown in the accompanying drawings illustrating this invention and inwhich- Figure 1 is a side elevation of an improved carbnreter of thischaracter with parts broken away and as taken on line 11, Fig. 2.

Fig. 2 is a. top plan view of-the parts shown in Fig. 1.

Fig. 3 is a sectional view taken on line 33. Fig. 1.

Fig. 4 is a 4 4. Fig. 2.

Fig. is a 55. Fig. 3.

Fig. 6 is a 6-6. Fig. 2.

Referring more particularly to the drawings. the numeral 10 designatesgenerally a body. having two chambers 11-l2 therein sectional view takenon line sectional view taken on line sectional view taken on lineadjacent each other and at one end of the body, the chamber 11 having anopen end provided with a closure 13 and through which closure is an airopening 14. The body is also provided with an enlarged portion 15opposite the chamber 11. Leading from the body 10 and havingcommunication with the outlet is a throat 16 of the carbureter which hascommunication with the inlet 17 of the engine; and the body is securedin position in any suitable manner, such as by means of fastening bolts18'.

Arranged to move within the chamber 11, which constitutes a cylinder. isa piston 19 adapted to be moved in one direction by a suitable spring20, arranged and housed within the cylinder and piston and coiled aboutthe piston rod 21.

The piston 19 is adapted to be moved in opposition to the cylinder 11 bythe suction of the engine, as will be hereafter more fully described.

The piston rod passes through a suitable bearing 22 in the Wall betweenthe cylinder 11 and the chamber 12, and also through a bearing 23 in theopposite wall and extends into the enlarged opening 15 of the body.Connected with the piston is a piston valve 24 which moves in acylindrical portion 25 of the enlarged end 15, and the cylinder ispreferably closed by a removable closure 26. hen the piston 19reciprocates in the cylinder 11, the piston valve 24 will alsoreciprocate in the cylinder 25 and this cylinder is preferably spacedfrom the wall of the enlarged outlet by means of suitable ribs 27 so asto form an air passage 28 around the cylinder 25. The end of thecylinder 15 adjacent the piston 24 is shaped to form a valve seat 30with which the valve 24 cooperates to open and clbse the air passage 28and thereby control the supply of air through the said passage to thethroat 16 which leads into the engine cylinder.

Arranged Within the throat 16 is a throttle valve 31. preferably of thebutterfly type. Leading from the cylinder 16 on the engine side of thethrottle 31 is a passage 32 which has communication as at 33 with thethroat 16, and a valve 34 is provided to close the passage 33. Thisvalve is preferably operated in one direction by means of aspring 35 andis operable at Will against the stress of the spring to close thepassage 33 by means of a suitable lever 36 pivotally mountedintermediate its ends as at 37, so that one end of the lever will engagethe valve 34 to shift it. Connected with the other end of the lever is awire 38 for actuating the lever and the valve; A suitable stop device 39may be provided for limiting the movement .of the lever in one directionunder the influence of theelastic member 35.

A. tank 40 is arranged in a convenient position, preferably below thethroat or passage 16 and is suppdnted preferably byl means of a nozzle41which passes throug suitable bearings in the throat or passage 16.

The nozzle has a shoulder 42 adapted to rest upon a suitable surface 43so that when provided with an inlet opening 46 preferby a shoe or cam 59ably adjacent the bottom of the tank, and is also provided with an inletopening 47 which is of a size somewhat-smaller than the opening 46. Thisinlet is disposed above the normal levelof the liquid and is of a verysmall size, preferably about a number 70 or a number 80 drill, and isprovided for the purpose of preventing the trapping of air in the upperpart of the tank. Li uid fuel will be drawn into the tank throug asupply pipe 48 which extends into the tank, terminating at any desiredelevation therein. From'the tank, the liquid fuel will be drawn througha strainer 49 which surrounds the tubular nozzle 41, and the strainer isheld in position in any desired. or suitable man-' ner. Projecting fromthe bottom of the tank is a flange 50, providedwith threads 51 for thereception of a cap 52 to form a chamber or inclosure or inclosedspacefor the fastening device or screw 45, to prevent the same from beingtampered with. A- needle valve 53 operates in the nozzle 41 and .isadapted to control outlet ports 54 which discharge into the throat orpassage 16. The valve is normally moved in a direction to open thenozzle by means of a spring 55 and this opening movement is limited bymeans of a rocker arm 56 which rests intermediate its ends upon a ballor roller bearing 57, seated in the end of the valve 53, the rocker armitself being referably provided with a recess for the reception of theball.

One end of the rocker arm 56 is preferably bent upwardly as at 58 to beengaged which latter is pivotally mounted as at 60 upon the end of theshaft 61 of the throttle 31, the latter being adapted to be rotated inits bearings by means of a in turn is connected with a rock crank arm63, to the end of which arm an operating bar or lever is connected, sothat when the throttle 31 is opened or closed, the mm or shoe 59 will bemoved over the ends 58 of the rocker arm 56 to depress that end. The camor shoe 59 is adapted to be adjusted with. respect to the throttle 31preferably bymeans of a thumb screw 63 against the end of which the camis adapted to engage, and by adjusting this screw 63, it will bemanifest that the position of the cam will be altered with the resultthat when operated the rocker arm 56 and the valve 53 will becorrespondingly moved. The other end of the rocker arm 56 engages alever 64, intermediate the ends of the latter, and this lever 64 ispivotally supported as at 65 by an arm 66, which latter shaft 67 to movetherewith. This rock shaft is in turn journaled in suitable supportingbearings, and is adapted to be rocked in a manner to be presently setforth, to raise or lower the arm 66 and thereby cause the arm 64 to beraised or lowered.

Loosely mounted upon the shaft 67 is a cam 68 which is arranged incontact with the end of the lever 64 and this cam 68 is provided with anarm 69 to which is connected an operating member 70 such as a wire,adapted to be actuated from the dash board of the vehicle, and by meansof which the cam 68 ma be turned about its pivot on the shaft 67. en thecam 68 is thus actuated, it will cause the lever 64 to be moved aboutits pivot- 65 and thereby move the needle valve 53. An adjustable stopdevice 71 may be provided for limiting the movement of the cam 68 in onedirect on.

From the mechanism thus far described, it will be manifest that thefulcrum. of the rocker arm changes according to which of the respectiveparts is operated. That is to say, when the parts are -in the positionshown in Fig. 4 and the throttle valve 31 is actuated, the cam or shoe59 is moved over the end 28 of the rocker arm 56't-o cause that end tobe depressed or to allow it to be raised by the spring 55,- according tothe direction of movement of the cam or shoe 59. During this operation,the rocker arm 56 will have a fulcrum upon the lever 64 which latter isheld against movement about its pivot by means of the cam 68. 7

When, however, the throttle 31 is not operated and the cam 68 is movedabout its pivot on the shaft 67, the rocker arm 56 will have its fulcrumon the end 58, resting against the cam or shoe 59, and the operation ofthis cam 68 will cause the lever 64 to be rocked about its pivot 65 tocontrol the actuation of the needle valve 53. The operation of theneedle valve 53 is also adapted to be controlled by the suction createdin the engine cylinder and to that end there is provided on the pistonrod 21 and preferably within the chamber 12 a collar 72 which ispreferably provided with a wedge-shaped surface 73. Mounted upon a rockshaft 74 'ournaled in suitable bear.

ings, preferably in the walls of the chamber 12, is a lever 75 whichlatter is preferably bifurcated and of a length to stand astride of thepiston rod 21, so as to engage with the wedge-shaped surface 73 of thecollar 7 2, and connected also with the rock shaft 74 is a cam 76 whichhas engagement with the arm 77 that is connected with the shaft 67 torotate therewith. The lever 75, cam 76, arm 77 and collar 72 are alllocated and housed within the chamber 12 to prevent tampering therewith,and access may be had to the chamber by means of a suitable removableclosure 78.

When the piston 19 is actuated by the engine suction manifested in thechamber 1.1; through the opening 32, it will be drawn inwardly againstthe stress of the spring 20.

This will cause the valve 24 to open to admit air into the throat orpassage 16, when the throttle 31 is opened. At the same time, the pistonrod being shifted, and the collar 72 having engagement with the lever75, the latter will be rocked, and this in turn will rock the cam 76 tocause the latter to rock the shaft. This operation will cause thearm 66to be rocked, which in turn will rock the lever 64 about its fulcrumformed by the contact of the end of the lever 64 with the cam 68. Thismovement of the lever 64 will actuate the rocker arm 56 about itsfulcrum between the end 58 of the arm and cam 59, to actuate the needlevalve 53. When the spring 20 operating on the piston 19 overcomes thesuction. in the engine cylinder, the cam 7 6 will be moved in theopposite direction to permit the needle valve 53 to be actuated by thespring 55.

Thus, it will be manifest that a single needle valve is providedwith'three separate and independent controlling means therefor.

In order to supply air to the mixture when the depression in thecarbureter throat or passage 16 reaches a predetermined point, to thinthe mixture, there may be provided an automatically operating air valve79 which controls an opening 80 in a casing 81, the valve beingcontrolled by a spring 82 adapted to be adjusted by a thumb nut 83. Thiscasing 81 has communication with an air jacket 84 preferably arrangedwithin the throat or passage 16 of the carbureter, and has communicationwith the chamber 81 by means of a passage 85, and the jacket 84 is alsoprovided with a discharge outlet 86 having communication with the throator passage 16 of the carbureter. This jacket 84 surrounds the nozzle 41and is of a size considerably larger than the external diameter of thenozzle, to form a chamber thercbehvecn, and the discharge outlets 54 ofthe nozzle 41 are disposed to discharge into the jacket 84. Thus, it.will be seen that when suction is created in the jacket 84, it will bemanifested in the chamber 81 to open the valve '79 against the stress ofthe spring 82. The amount of air thus supplied will be controlled by thesuction in the jacket and the tension of the ,spring 82.

It is thought that the operation of this improved carbureter will beclearly understood from the foregoing description, but briefly stated,it is as follows:

To start the engine, the throttle 62 is first opened slightly and thecam 68 is shifted forwardly, so that the needle valve 53 will operate toenlarge the fuel orifice. The valve 34 is then actuated to close thepassage 33 between the throat of the carbureter and the chamber 11,thereby preventing any suction in the engine cylinder from beingmanifested in the cylinder 11, and also preventing any air from flowingthrough the passages 28. as the valve will be maintained closed by thespring 20. A turn or two of the engine crank will be suflicient to primeand start the engine, after which the valve 34 is released to open thepassage 32, so that the engine suction will be manifested in thecylinder 11. This suction will actuate the piston 19 against the stressof the spring 20 and at the same time will shift the valve 24 to openthe passage 28. The needle valve 53 will be simultaneously actuated bythe movement of the piston through the medium of the collar 72, lever 75, rock shaft 67 arm 66 and lever 64 to reduce the flow of fuel throughthe fuel orifice After the engine is started, the actuation of thecarbureter will then be automatic, the piston .19

-inoving back and forth according to the in the carbureter throat 16reaches a prc- 7 determined point, thus admitting air around the fuelorifice 54 and tending to thin the mixture.

This valve also operates during idling of the engine and also at highspeeds, aud the' tension of the spring 82 is such that the valve 79 willremain closed at intermediate speeds.

When the engine is idling the throttle 31 is nearly closed, therebyproducing a high vacuum or the highest vacuum possible to be produced bythe engine and which vacuum is manifested in the throat of thecarbureter adjacent the valve 79. This vacuum will therefore open thevalve. When the air throttle is wide open, the engine also creates avacuum that w1ll be sufiiclent to open the valve 7 9. At intermediatespeeds the engine suction will not be suificient to valve 79.

.The housing or chamber 12 has nolcommunication with outside air and istightly closeg, thereby rendering the. same dustroo P The opening 14provided'in the cylinder 11 is of a size to admit atmospheric pressurefor the rapid operation of the iston 19, and is small enough so that airwlll be tem porarily confined between the end of the piston and the head13 of the cylinder, so as to act as a cushion for the piston in theevent of back fire in the engine.

That is to say, the inward movement of the piston 19 caused by the en'ne suction is comparatively slow, while t e receding movement, due tothe action of the spring, supplemented by the force upon the pistonmanifested by the back fire, is very rapid so cannot pass out of theopening 14: with such rapidity, and is therefore temporarily trapped orpartially compressed and acts as a cushion.

While the preferred form of the invention has been herein shown anddescribed, it is to be understood that many changes may be made in thedetails of constructlon and in the combination and arrangement of theseveral parts, within the scope of the claims, without departing fromthe spirit of this invention.

What is claimed as new is:

1. A carbureter embodying a fuel supply nozzle, a needle valve forcontrolling the nozzle, means tending normally to actuate the valve inone direction, a rocker arm detached from and supported intermediateitsends upon the end of and entirely by the needle valve, an air throttlevalve, means for actuating the latter, a cam device connected with theair throttle valve to operate in unison therewith, the said cam devicebeing detached from and engaging one end of the rocker arm to actuatethe needle valve in opposition to the first recited means, an actuatingmember also detached from and operating upon the opposite end of therocker arm to actuate "the needle valve in opposition to the firstrecited means, and means for operating the said actuating member, thesaid actuating member and the cam device each serving as a fulcrum (forthe red spective ends of the rocker arm.

2. A carbureter embodying a fuel supply nozzle, a needle valve forcontrolling the nozzle, means tending normally to actuate the valve inone direction, a rocker arm detached from and supported intermediate itsends upon the end of and entirely by the needle valve, an air throttlevalve, means for actuating the latter, a cam device connected open thewith the air throttle valve to operate in unison therewith, the said camdevice bein de-' tached from and engaging one end 0 the rocker arm toactuate the needle valve in opposition to the first recited means, anactuating member also detached from and operating upon the opposite endof the rocker arm to actuate the needle valve in opposition to the firstrecited means, and means for o erating the said actuating member, thesaid actuating member and the cam device each serving as a fulcrum forthe respective ends of the rocker arm and each operating to actuate theneedle valve in the same direction.

3,. A carbureter embodying a fuel supply nozzle, a needle valve forcontrolling the nozzle, means tending normally to actuate the valve inone direction, a rocker arm detached from and supported intermediate itsends upon the end of and entirely by the needle valve, an air throttlevalve, means for actuating the latter, a cam device connected with theair throttle valve to operate in unison therewith, the said cam devicebeing detached from and engaging one end 'rod connected with the piston,a rock shaft connected to said actuating member for operating thelatter, and an operative connection between the rock shaft and the saidpiston rod.

4. A carbureter embodying a' fuel supply nozzle, a needle valve forcontrolling the nozzle, means tending normally to actuate the valve inone direction, a rocker arm de-- tached from but supported intermediateits ends upon the end of and entirely by the needle valve, an airthrottle valve, means for actuating the latter, a cam device connectedwith the air throttle valve to operate in unison therewith, the said camdevice being detached from but engaging one end. of the rocker arm toactuate'the needle valve in opposition to the first-recited means, anactuating member detached from and operating upon the opposite end ofthe rocker arm to actuate the needlevalve in opposition to the firstrecited means, a piston operable in one direction by engine suction, apiston rod connected with the piston, a rock shaft connected with thesaid actuating member for operating the latter, a shoulder the valve inone direction, a rocker arm'detached from but supported upon the end ofthe needle valve and entirely thereby, an air throttle valve, means foractuating the latter, a cam device pivotally connected with the airthrottle valve and movable therewith, said cam device being detachedfrom but engaging and resting upon one end of the rocker arm, anadjustable stop device carried with the'air throttle valve and engagingthe cam to vary the position of the cam with respect to the air throttlevalve.

f said cam operating to actuate the needle valve, an actuating memberdetached from and operating upon the other end of the rocker arm toactuate the needle valve in the same direction as it is operated, by thesaid cam, and'means operatingautomatically to operate the said actuatingmember.

In testimony whereof I have signed my name to this specification, onthis 13th day of SeptembenvA. D. 1918.

EDWARD MCCARTHY.

